/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: ToTextStream.java,v 1.2.4.1 2005/09/21 10:35:34 pvedula Exp $
 */
package com.sun.org.apache.xml.internal.serializer;

import java.io.IOException;

import com.sun.org.apache.xml.internal.serializer.utils.MsgKey;
import com.sun.org.apache.xml.internal.serializer.utils.Utils;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;

/**
 * This class is not a public API.
 * It is only public because it is used in other packages.
 * This class converts SAX or SAX-like calls to a
 * serialized document for xsl:output method of "text".
 * @xsl.usage internal
 */
public final class ToTextStream extends ToStream {

    /**
     * Default constructor.
     */
    public ToTextStream() {
        super();
    }

    /**
     * Receive notification of the beginning of a document.
     *
     * <p>The SAX parser will invoke this method only once, before any
     * other methods in this interface or in DTDHandler (except for
     * setDocumentLocator).</p>
     *
     * @throws org.xml.sax.SAXException Any SAX exception, possibly
     *            wrapping another exception.
     *
     * @throws org.xml.sax.SAXException
     */
    protected void startDocumentInternal() throws org.xml.sax.SAXException {
        super.startDocumentInternal();

        m_needToCallStartDocument = false;

        // No action for the moment.
    }

    /**
     * Receive notification of the end of a document.
     *
     * <p>The SAX parser will invoke this method only once, and it will
     * be the last method invoked during the parse.  The parser shall
     * not invoke this method until it has either abandoned parsing
     * (because of an unrecoverable error) or reached the end of
     * input.</p>
     *
     * @throws org.xml.sax.SAXException Any SAX exception, possibly
     *            wrapping another exception.
     *
     * @throws org.xml.sax.SAXException
     */
    public void endDocument() throws org.xml.sax.SAXException {
        flushPending();
        flushWriter();
        if (m_tracer != null)
            super.fireEndDoc();
    }

    /**
     * Receive notification of the beginning of an element.
     *
     * <p>The Parser will invoke this method at the beginning of every
     * element in the XML document; there will be a corresponding
     * endElement() event for every startElement() event (even when the
     * element is empty). All of the element's content will be
     * reported, in order, before the corresponding endElement()
     * event.</p>
     *
     * <p>If the element name has a namespace prefix, the prefix will
     * still be attached.  Note that the attribute list provided will
     * contain only attributes with explicit values (specified or
     * defaulted): #IMPLIED attributes will be omitted.</p>
     *
     *
     * @param namespaceURI The Namespace URI, or the empty string if the
     *        element has no Namespace URI or if Namespace
     *        processing is not being performed.
     * @param localName The local name (without prefix), or the
     *        empty string if Namespace processing is not being
     *        performed.
     * @param name The qualified name (with prefix), or the
     *        empty string if qualified names are not available.
     * @param atts The attributes attached to the element, if any.
     * @throws org.xml.sax.SAXException Any SAX exception, possibly
     *            wrapping another exception.
     * @see #endElement
     * @see org.xml.sax.AttributeList
     *
     * @throws org.xml.sax.SAXException
     */
    public void startElement(String namespaceURI, String localName, String name, Attributes atts) throws org.xml.sax.SAXException {
        // time to fire off startElement event
        if (m_tracer != null) {
            super.fireStartElem(name);
            this.firePseudoAttributes();
        }
        return;
    }

    /**
     * Receive notification of the end of an element.
     *
     * <p>The SAX parser will invoke this method at the end of every
     * element in the XML document; there will be a corresponding
     * startElement() event for every endElement() event (even when the
     * element is empty).</p>
     *
     * <p>If the element name has a namespace prefix, the prefix will
     * still be attached to the name.</p>
     *
     *
     * @param namespaceURI The Namespace URI, or the empty string if the
     *        element has no Namespace URI or if Namespace
     *        processing is not being performed.
     * @param localName The local name (without prefix), or the
     *        empty string if Namespace processing is not being
     *        performed.
     * @param name The qualified name (with prefix), or the
     *        empty string if qualified names are not available.
     * @throws org.xml.sax.SAXException Any SAX exception, possibly
     *            wrapping another exception.
     *
     * @throws org.xml.sax.SAXException
     */
    public void endElement(String namespaceURI, String localName, String name) throws org.xml.sax.SAXException {
        if (m_tracer != null)
            super.fireEndElem(name);
    }

    /**
     * Receive notification of character data.
     *
     * <p>The Parser will call this method to report each chunk of
     * character data.  SAX parsers may return all contiguous character
     * data in a single chunk, or they may split it into several
     * chunks; however, all of the characters in any single event
     * must come from the same external entity, so that the Locator
     * provides useful information.</p>
     *
     * <p>The application must not attempt to read from the array
     * outside of the specified range.</p>
     *
     * <p>Note that some parsers will report whitespace using the
     * ignorableWhitespace() method rather than this one (validating
     * parsers must do so).</p>
     *
     * @param ch The characters from the XML document.
     * @param start The start position in the array.
     * @param length The number of characters to read from the array.
     * @throws org.xml.sax.SAXException Any SAX exception, possibly
     *            wrapping another exception.
     * @see #ignorableWhitespace
     * @see org.xml.sax.Locator
     */
    public void characters(char ch[], int start, int length) throws org.xml.sax.SAXException {

        flushPending();

        try {
            if (inTemporaryOutputState()) {
                /* leave characters un-processed as we are
                 * creating temporary output, the output generated by
                 * this serializer will be input to a final serializer
                 * later on and it will do the processing in final
                 * output state (not temporary output state).
                 *
                 * A "temporary" ToTextStream serializer is used to
                 * evaluate attribute value templates (for example),
                 * and the result of evaluating such a thing
                 * is fed into a final serializer later on.
                 */
                m_writer.write(ch, start, length);
            } else {
                // In final output state we do process the characters!
                writeNormalizedChars(ch, start, length, m_lineSepUse);
            }

            if (m_tracer != null)
                super.fireCharEvent(ch, start, length);
        } catch (IOException ioe) {
            throw new SAXException(ioe);
        }
    }

    /**
     * If available, when the disable-output-escaping attribute is used,
     * output raw text without escaping.
     *
     * @param ch The characters from the XML document.
     * @param start The start position in the array.
     * @param length The number of characters to read from the array.
     *
     * @throws org.xml.sax.SAXException Any SAX exception, possibly
     *            wrapping another exception.
     */
    public void charactersRaw(char ch[], int start, int length) throws org.xml.sax.SAXException {

        try {
            writeNormalizedChars(ch, start, length, m_lineSepUse);
        } catch (IOException ioe) {
            throw new SAXException(ioe);
        }
    }

    /**
     * Normalize the characters, but don't escape.  Different from
     * SerializerToXML#writeNormalizedChars because it does not attempt to do
     * XML escaping at all.
     *
     * @param ch The characters from the XML document.
     * @param start The start position in the array.
     * @param length The number of characters to read from the array.
     * @param useLineSep true if the operating systems
     * end-of-line separator should be output rather than a new-line character.
     *
     * @throws IOException
     * @throws org.xml.sax.SAXException
     */
    void writeNormalizedChars(final char ch[], final int start, final int length, final boolean useLineSep) throws IOException, org.xml.sax.SAXException {
        final String encoding = getEncoding();
        final java.io.Writer writer = m_writer;
        final int end = start + length;

        /* copy a few "constants" before the loop for performance */
        final char S_LINEFEED = CharInfo.S_LINEFEED;

        // This for() loop always increments i by one at the end
        // of the loop.  Additional increments of i adjust for when
        // two input characters (a high/low UTF16 surrogate pair)
        // are processed.
        for (int i = start; i < end; i++) {
            final char c = ch[i];

            if (S_LINEFEED == c && useLineSep) {
                writer.write(m_lineSep, 0, m_lineSepLen);
                // one input char processed
            } else if (m_encodingInfo.isInEncoding(c)) {
                writer.write(c);
                // one input char processed
            } else if (Encodings.isHighUTF16Surrogate(c)) {
                final int codePoint = writeUTF16Surrogate(c, ch, i, end);
                if (codePoint != 0) {
                    // I think we can just emit the message,
                    // not crash and burn.
                    final String integralValue = Integer.toString(codePoint);
                    final String msg = Utils.messages.createMessage(MsgKey.ER_ILLEGAL_CHARACTER, new Object[] { integralValue, encoding });

                    //Older behavior was to throw the message,
                    //but newer gentler behavior is to write a message to System.err
                    //throw new SAXException(msg);
                    System.err.println(msg);

                }
                i++; // two input chars processed
            } else {
                // Don't know what to do with this char, it is
                // not in the encoding and not a high char in
                // a surrogate pair, so write out as an entity ref
                if (encoding != null) {
                    /* The output encoding is known,
                     * so somthing is wrong.
                     */

                    // not in the encoding, so write out a character reference
                    writer.write('&');
                    writer.write('#');
                    writer.write(Integer.toString(c));
                    writer.write(';');

                    // I think we can just emit the message,
                    // not crash and burn.
                    final String integralValue = Integer.toString(c);
                    final String msg = Utils.messages.createMessage(MsgKey.ER_ILLEGAL_CHARACTER, new Object[] { integralValue, encoding });

                    //Older behavior was to throw the message,
                    //but newer gentler behavior is to write a message to System.err
                    //throw new SAXException(msg);
                    System.err.println(msg);
                } else {
                    /* The output encoding is not known,
                     * so just write it out as-is.
                     */
                    writer.write(c);
                }

                // one input char was processed
            }
        }
    }

    /**
     * Receive notification of cdata.
     *
     * <p>The Parser will call this method to report each chunk of
     * character data.  SAX parsers may return all contiguous character
     * data in a single chunk, or they may split it into several
     * chunks; however, all of the characters in any single event
     * must come from the same external entity, so that the Locator
     * provides useful information.</p>
     *
     * <p>The application must not attempt to read from the array
     * outside of the specified range.</p>
     *
     * <p>Note that some parsers will report whitespace using the
     * ignorableWhitespace() method rather than this one (validating
     * parsers must do so).</p>
     *
     * @param ch The characters from the XML document.
     * @param start The start position in the array.
     * @param length The number of characters to read from the array.
     * @throws org.xml.sax.SAXException Any SAX exception, possibly
     *            wrapping another exception.
     * @see #ignorableWhitespace
     * @see org.xml.sax.Locator
     */
    public void cdata(char ch[], int start, int length) throws org.xml.sax.SAXException {
        try {
            writeNormalizedChars(ch, start, length, m_lineSepUse);
            if (m_tracer != null)
                super.fireCDATAEvent(ch, start, length);
        } catch (IOException ioe) {
            throw new SAXException(ioe);
        }
    }

    /**
     * Receive notification of ignorable whitespace in element content.
     *
     * <p>Validating Parsers must use this method to report each chunk
     * of ignorable whitespace (see the W3C XML 1.0 recommendation,
     * section 2.10): non-validating parsers may also use this method
     * if they are capable of parsing and using content models.</p>
     *
     * <p>SAX parsers may return all contiguous whitespace in a single
     * chunk, or they may split it into several chunks; however, all of
     * the characters in any single event must come from the same
     * external entity, so that the Locator provides useful
     * information.</p>
     *
     * <p>The application must not attempt to read from the array
     * outside of the specified range.</p>
     *
     * @param ch The characters from the XML document.
     * @param start The start position in the array.
     * @param length The number of characters to read from the array.
     * @throws org.xml.sax.SAXException Any SAX exception, possibly
     *            wrapping another exception.
     * @see #characters
     *
     * @throws org.xml.sax.SAXException
     */
    public void ignorableWhitespace(char ch[], int start, int length) throws org.xml.sax.SAXException {

        try {
            writeNormalizedChars(ch, start, length, m_lineSepUse);
        } catch (IOException ioe) {
            throw new SAXException(ioe);
        }
    }

    /**
     * Receive notification of a processing instruction.
     *
     * <p>The Parser will invoke this method once for each processing
     * instruction found: note that processing instructions may occur
     * before or after the main document element.</p>
     *
     * <p>A SAX parser should never report an XML declaration (XML 1.0,
     * section 2.8) or a text declaration (XML 1.0, section 4.3.1)
     * using this method.</p>
     *
     * @param target The processing instruction target.
     * @param data The processing instruction data, or null if
     *        none was supplied.
     * @throws org.xml.sax.SAXException Any SAX exception, possibly
     *            wrapping another exception.
     *
     * @throws org.xml.sax.SAXException
     */
    public void processingInstruction(String target, String data) throws org.xml.sax.SAXException {
        // flush anything pending first
        flushPending();

        if (m_tracer != null)
            super.fireEscapingEvent(target, data);
    }

    /**
     * Called when a Comment is to be constructed.
     * Note that Xalan will normally invoke the other version of this method.
     * %REVIEW% In fact, is this one ever needed, or was it a mistake?
     *
     * @param   data  The comment data.
     * @throws org.xml.sax.SAXException Any SAX exception, possibly
     *            wrapping another exception.
     */
    public void comment(String data) throws org.xml.sax.SAXException {
        final int length = data.length();
        if (length > m_charsBuff.length) {
            m_charsBuff = new char[length * 2 + 1];
        }
        data.getChars(0, length, m_charsBuff, 0);
        comment(m_charsBuff, 0, length);
    }

    /**
     * Report an XML comment anywhere in the document.
     *
     * This callback will be used for comments inside or outside the
     * document element, including comments in the external DTD
     * subset (if read).
     *
     * @param ch An array holding the characters in the comment.
     * @param start The starting position in the array.
     * @param length The number of characters to use from the array.
     * @throws org.xml.sax.SAXException The application may raise an exception.
     */
    public void comment(char ch[], int start, int length) throws org.xml.sax.SAXException {

        flushPending();
        if (m_tracer != null)
            super.fireCommentEvent(ch, start, length);
    }

    /**
     * Receive notivication of a entityReference.
     *
     * @param name non-null reference to the name of the entity.
     *
     * @throws org.xml.sax.SAXException
     */
    public void entityReference(String name) throws org.xml.sax.SAXException {
        if (m_tracer != null)
            super.fireEntityReference(name);
    }

    /**
     * @see ExtendedContentHandler#addAttribute(String, String, String, String, String)
     */
    public void addAttribute(String uri, String localName, String rawName, String type, String value, boolean XSLAttribute) {
        // do nothing, just forget all about the attribute
    }

    /**
     * @see org.xml.sax.ext.LexicalHandler#endCDATA()
     */
    public void endCDATA() throws SAXException {
        // do nothing
    }

    /**
     * @see ExtendedContentHandler#endElement(String)
     */
    public void endElement(String elemName) throws SAXException {
        if (m_tracer != null)
            super.fireEndElem(elemName);
    }

    /**
     * From XSLTC
     */
    public void startElement(String elementNamespaceURI, String elementLocalName, String elementName) throws SAXException {
        if (m_needToCallStartDocument)
            startDocumentInternal();
        // time to fire off startlement event.
        if (m_tracer != null) {
            super.fireStartElem(elementName);
            this.firePseudoAttributes();
        }

        return;
    }

    /**
     * From XSLTC
     */
    public void characters(String characters) throws SAXException {
        final int length = characters.length();
        if (length > m_charsBuff.length) {
            m_charsBuff = new char[length * 2 + 1];
        }
        characters.getChars(0, length, m_charsBuff, 0);
        characters(m_charsBuff, 0, length);
    }

    /**
     * From XSLTC
     */
    public void addAttribute(String name, String value) {
        // do nothing, forget about the attribute
    }

    /**
     * Add a unique attribute
     */
    public void addUniqueAttribute(String qName, String value, int flags) throws SAXException {
        // do nothing, forget about the attribute
    }

    public boolean startPrefixMapping(String prefix, String uri, boolean shouldFlush) throws SAXException {
        // no namespace support for HTML
        return false;
    }

    public void startPrefixMapping(String prefix, String uri) throws org.xml.sax.SAXException {
        // no namespace support for HTML
    }

    public void namespaceAfterStartElement(final String prefix, final String uri) throws SAXException {
        // no namespace support for HTML
    }

    public void flushPending() throws org.xml.sax.SAXException {
        if (m_needToCallStartDocument) {
            startDocumentInternal();
            m_needToCallStartDocument = false;
        }
    }
}
